1. Field of the Invention
The invention generally relates to a light emitting device, and more particularly, to a light emitting diode (LED) module.
2. Description of Related Art
Since light emitting diodes (LEDs) have advantages such as low power consumption and high brightness, LEDs are widely used in different fields, such as displays, lighting, and indicating lights. In addition, in the established color gamut of the National Television Standard Committee (NTSC), LEDs also have excellent color space. Thus, LEDs have gradually replaced cold cathode fluorescent lamps (CCFLs), becoming one of the major parts in a backlight module of display panels.
Taking the current popular liquid crystal display as an example, an LED backlight is already gradually becoming a mainstream product. In the LED backlight fabrication process, accumulation and discharge of static electricity from workers or machines are inevitable. The static electricity discharges electricity to an LED package through lower resistance routes, and causes the LED chip in the LED package to be damaged because of the discharged static electricity. In conventional technology, many prevention designs to avoid LED chips from being damaged by the discharged electricity are brought up, one of which is shown in FIG. 1.
FIG. 1 is a schematic view of a conventional LED module. Referring to FIG. 1, the conventional LED module includes a circuit board 100 and an LED package 200. The circuit board 100 comprises a plurality of driving signal wirings 102 and a ground wiring 104. The LED package 200 comprises two signal leads 202, an LED chip 206, a transparent encapsulation member 208a, an opaque encapsulation member 208b, and a bonding wire 210. The LED chip 206 is electrically connected to the driving signal wirings 102 through the signal leads 202 and the bonding wire 210. The ground wiring 104 is disposed only on all edges of the circuit board 100 and surrounds the LED package 200. Since the ground wiring 104 is capable of transmitting the static electricity out of the circuit board 100 along the lateral direction (x-y plane), it is difficult for the static electricity to enter the LED package 200, and thereby protecting the LED chip 206.
However, since the thickness of display panels and similar products are gradually made thinner, borders of the display panels are made narrower, and the circuit board 100 of the LED package must also be made smaller. Following the trend, the arrangement area of the ground wiring 104 is reduced, causing the ground wiring 104 to be unable to completely surround the LED package 200. In addition, when the static electricity is not discharged along the lateral direction (x-y plane), such as when the static electricity is discharged along the vertical direction (z-axis direction), the static electricity enters the LED package 200 from a signal lead which is higher than the ground wiring 104, and causes damage to the LED chip 206. In other words, the static electricity protection design shown in FIG. 1 is limited to prevent the damage caused by static electricity discharged along x-y plane (or namely two-dimensional protection), and is unable to achieve a three-dimensional protection (or namely x-y-z space). Thus, how to effectively reduce the probability of damage resulted from the static electricity discharge has become an important issue to be solved.